Issued for the opening of a new PO in Bucharest.
The originals were engraved and perfed 13.5X14
Genuine issues all have a common feature - a dot below the top "R"
There are 2 or 3 different forgeries.
Unfortunately, I have no specifics on how to distinguish them.
Here are comparisons of genuine (left) and forgery (right)
The 15b is the only counterfeit that measured 13.5 X 14, like the genuines. 25b and othersforgery examples are 13.5 X 13. The 40b the forgery is 13.5 X 13.5.
Aside from being lithographs on white paper, forgeries have obvious color differences.